The invention pertains to mirrors, and more particularly, to decorating mirrors and other products.
Mirrors have been available for centuries. Mirrors are optical devices, with a smooth, polished surface that forms images by the reflection of rays of light. Mirrors are useful to view a person's own reflection or image, as well as to reflect light for a variety of purposes. Historically, polished metal and other shiny surfaces functioned as mirrors.
Mirrors have been made of brass, and mirrors of bronze were in use among the ancient Egyptians, Greeks, and Romans. Polished silver was also used by the Greeks and Romans to produce reflections. Crude forms of glass mirrors were first made in Venice in 1300. By the end of the 17th century, mirrors were made in Britain and the manufacture of mirrors developed subsequently into an important industry in the other European countries and in the United States.
Glass mirrors were later developed with better reflective qualities and less distortion. One method of previously making glass mirrors included backing a sheet of glass with an amalgam of mercury and tin. The surface of the mirror was overlaid with sheets of tinfoil that were rubbed down smooth and covered with mercury. A woolen cloth was held firmly over the surface by iron weights for about a day. The glass was then inclined and the excess mercury drained away, leaving a lustrous inner surface. The first attempt to back the glass with a solution of silver may have been made by the German chemist Justus von Liebig in 1836. Various methods have been developed since then that depend on the chemical reduction of silver salt to metallic silver.
In the manufacture of some mirrors today, in cases where the above principle is utilized, the plate glass is cut to size, and blemishes are removed by polishing with rouge. The glass is scrubbed and flushed with a reducing solution such as stannous chloride before silver is applied, and the glass is then placed on a hollow, cast-iron tabletop, covered with felt, and kept warm by steam. A solution of silver nitrate is poured on the glass and left undisturbed for about an hour. The silver nitrate is reduced to a metallic silver and a lustrous deposit of silver gradually forms. The deposit is dried, coated with shellac, and painted.
In other methods of mirror production, the silver solution is added with a reducing agent, such as formaldehyde of glucose. Silvering chemicals are often applied in spray form. Special mirrors are sometimes coated with the metal in the form of vapor obtained by vaporizing silver electrically in a vacuum. Large mirrors have been coated with aluminum in the same way.
Recently, plastic mirrors have been developed. Plastic mirrors are lighter than glass mirrors and will not shatter as readily as glass. Some plastic mirrors, however, do not provide the same optical qualities, clarity and reflectivity as glass mirrors. Moreover, plastic mirrors can distort and warp at high temperatures.
In the past, glass panes, glass windows, glass shower doors, and glass mirrors have been decorated in a variety of ways. Glass panes, glass windows, glass shower doors and glass mirrors have been chemically etched, such as with a fluoride or chloride-containing gas to frost the desired areas or surfaces of the glass panes, glass windows, glass shower doors or glass mirrors. Glass panes have also been sandblasted. The front surfaced of glass panes, glass windows, glass shower doors and glass mirrors have also been painted, such as with a brush, by stencils, spray painting, or by silk screening. Painted surfaces, however, often readily chip and degrade over time from use, cleaning, wear and tear, as well as from prolonged environmental exposure to sunlight, acid rain, and pollutants. Mechanical engraving of glass with awls and hand scribes have been attempted, but the end results are generally crude and lack detail, luster, and aesthetic appeal.
It is, therefore, desirable to produce an improved decorative display assembly, such as a mirror, in a manner which overcomes most, if not all, of the preceding problems.